Control device for compressor engines



Dec. 27, 1927. 1,654,081

| F. HOFFMAN CONTROL DEVICE FOR COMPRESSOR ENGINES Filed June 24, 1924 E 5, IN VE/V 70R g ,7 Zea/1 E flafi man ME BrLATm/P/VEY Patented Dec. 27, .1927.

UNITED STATES 1,654,081 PATENT OFFICE.

LEON F. HOFFMAN, OF FRANKLIN, PENNSYLVANIA, ASSIGNOB TO CHICAGO PNEU- MATIC TOOL COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

CONTROL DEVICE FOR COMPRESSOR ENGINES.

Application filed June 24, 1924. Serial No. 722,180.

This invention relates to automatic control systems for compre ors and their driving engines and more particularly to fluid pressure operated. throttles for the latter.

One object 01' the inveiiition is to provide a simple, ellicicnt throttle control device which can be easily and quickly installed on the engine to be controlled. i-lnother object is to form such a device as a. unit to be in sorted. in the tuel or motive agent supply conduit ot the engine. Other objects will be apparent from the detailed description of the invention which follows.

In order to illustrate the invention and. the manner of its use, one concrete embodiment is shown in the accompanying drawings, in which:

Fig. 1 is a diagralnmatieal view partly in section disclosing a typical installation ot the invention with the operative parts as sociated therewith;

Fig. 2 is a rear elevational view ot the throttle blocl'c shown. in Fig. 1 partly in section on the line ai of Fig. 3, the pneir niatic device having been operated to move the throttle valve to throttling position; and

Fig. 3 is a sectional view substantially on. the broken line 3--3 ot Fig. 2.

The pneumatic throttle device comprising the present invention is disclosed in Fig. 1 in a. typical compressor installation wherein the driving engine A. of the compressor 'ljraglnentarily disclosed at B is throttled coordinately with the unloading of the co1nprcssor. The connarcssor may be unloaded by any suitable fluid pressure apparatus such as an unloader or pilot valve G connected to receiver ressure by pipe and discharging pressure fluid when the receiver pressure reaches a predetermined degree through a pipe 0 to actuate an unloading valve D and through a branch connection 0 to operate the pneumatic throttle device presently to be described. The unloader valve shown oil the type disclosed in U. S. Patent No. 1,221,272 issued Mayfll, 1917 to W. ll. Callan et al. and the unloading valve is ol the type disclosed in ll. S. Patent No. 1,275,843 issued August 13, 1918 to V. H. Callan, but any suitable or desired apparatus adapted to function in the manner described may he used. 1

The throttle device comprises a block or casing 4.- having a bore or passage 5 there through and provided at its extremities with flanges b arrai'iged to register with and to be secured to similar flanges on the carburetor E and. intake manl'lold F respectively of the internal cornbrn tion engine A, the device thus being interposed as a unit between the said portions of the engine structure and forming a part of the motive agent. supply conduit tothe engine. lvlounted within the central bore or motive agent passage 5 of block 4 a suitable throttle valve which may take the form of: the ordinary butterfly valve 7 secured to a shattS join-nailed in bearings in the sides of the block and normally maintained in the open position shown in Fig. 1 by a. coiled. spring 9 having one end 10 anchored. in a in the block and the other end 11. engaging a lever air-111 12 which is termed with a collar 13 fitting the projecting end of shatt 8 and keyed thereto by a pin "1 1-. On the rear ot block d and preferably intcgral therewith is a cylinder 15 into the outer open end of which pipe c from unloader valve C is suitably connected. A piston 16 is disposed within cylinder 15 for sliding movement and provided with a stem 17 extending therebeyond to engage the lever arm 12 on shaft 8 so that when the unloader valve C is actuated, fluid pr ssure discharged by the latter into pipe 0" torces piston 16 outwardly to move lever 12 to the position shown in Fig 2, which movei'nent rotates throttle valve 7 within passage 5 to throttling position indicated. in dotted out.- line in Fig. 2. The throt ling position of valve 71 is readily adjusted by means oil a stop in the form of a screw bolt 18 provided with a lock nut 19. Bolt 18 screws into an opening 20 in a. guard plate 21 which arches over the externally projecting end. of shatt 8 and is preferably, though not necessarily, formed integral with the block 4 and the cylinder. 15. In the operation of the device, the motive fluid which is released by unloader valve C to act upon the piston. 16 is relieved. by the unloader valve when the required. pressure talls below the iredeter mined amount and the throttle valve 7 and piston 16 are restored to their normally open and retracted positions, respectively, through the action of spring 9.

From the above it will be a iparent that the throttle device herein disclosed provides means for readily adiupting the internal combustion engine of an engine driven compressor to automatic control coordinate with and responsive to the unloading of a com pressor, that the installation of the device as a unit is quickly effected since it requires no nges 1n the engine itself nor in the engines equipment, that the device is self contained and is readily adjusted to proper idling position for the engine Without any change in the carburetor adjustment, that the throttle device assures positive automatic control of the engine, and that the throttle block can be easily and cheaply manufactured and assembled.

While but a single preferred form of the invention has been herein'shown and de scribed, it is to be understood that the invention covers and is intended to cover all ehangves, modifications and adaptations Within the scope of the appended claims.

I claim as my invention:

1. A throttle device for internal combustion engines comprising a block arranged to be interposed between the carburetor and the intake manifold of the engine, said block having a bore therethrough arranged to form a part of the intake passage, a throttle valve in said bore having an operating shaft projecting outside said block, a torsion spring on the projecting portion of said shaft yieldingly to hold said valve in open POSitlOHfRH arm on said shaft, an adjustable stop in the path of movement of said arm, means at least partly enclosing said projecting shaft and said arm and supcylinder sufficient to overcome porting said stop, a cylinder in line with said stop, and a. piston recipmcably ar ranged within said cylinder and having a projecting stem arranged to engage said arm to move said valve toward closed position on admission of fluid pressure to said said spring. 2. A throttle device for controlling; the driving engine of a compressor comprising a. block arranged to be interposed between the carburetor and the intake manifold of the engine, saidblock having a here therethrongh to form a part of the intake passage, a throttle valve in said bore having an operating shaft projecting outside said block, a torsion spring on the projecting portion of said shaft yieldingly to hold said valve in open position, an arm on said shaft, an adjustable stop in the path of movement of said arm, a guard plate integral with said block extending over and partly inclosing the projecting portion of said shaft and said spring, said plate forming a support for said adjustable stop, and means for actuating said valve under control of the fluid pressure produced by the compressor comprising a cylinder integral with said block and said plate, and a piston reciprocable within said cylinder and having av stem to engage said arm.

Signed by me at Franklin, this 16th day of June, 1924.

LEON F. HOFFMAN.

Pennsylvania, 

